# dlatzm.f - Man Page

SRC/DEPRECATED/dlatzm.f

## Synopsis

### Functions/Subroutines

subroutine dlatzm (side, m, n, v, incv, tau, c1, c2, ldc, work)
DLATZM

## Function/Subroutine Documentation

### subroutine dlatzm (character side, integer m, integer n, double precision, dimension( * ) v, integer incv, double precision tau, double precision, dimension( ldc, * ) c1, double precision, dimension( ldc, * ) c2, integer ldc, double precision, dimension( * ) work)

DLATZM

Purpose:

``` This routine is deprecated and has been replaced by routine DORMRZ.

DLATZM applies a Householder matrix generated by DTZRQF to a matrix.

Let P = I - tau*u*u**T,   u = ( 1 ),
( v )
where v is an (m-1) vector if SIDE = 'L', or a (n-1) vector if
SIDE = 'R'.

If SIDE equals 'L', let
C = [ C1 ] 1
[ C2 ] m-1
n
Then C is overwritten by P*C.

If SIDE equals 'R', let
C = [ C1, C2 ] m
1  n-1
Then C is overwritten by C*P.```
Parameters

SIDE

```          SIDE is CHARACTER*1
= 'L': form P * C
= 'R': form C * P```

M

```          M is INTEGER
The number of rows of the matrix C.```

N

```          N is INTEGER
The number of columns of the matrix C.```

V

```          V is DOUBLE PRECISION array, dimension
(1 + (M-1)*abs(INCV)) if SIDE = 'L'
(1 + (N-1)*abs(INCV)) if SIDE = 'R'
The vector v in the representation of P. V is not used
if TAU = 0.```

INCV

```          INCV is INTEGER
The increment between elements of v. INCV <> 0```

TAU

```          TAU is DOUBLE PRECISION
The value tau in the representation of P.```

C1

```          C1 is DOUBLE PRECISION array, dimension
(LDC,N) if SIDE = 'L'
(M,1)   if SIDE = 'R'
On entry, the n-vector C1 if SIDE = 'L', or the m-vector C1
if SIDE = 'R'.

On exit, the first row of P*C if SIDE = 'L', or the first
column of C*P if SIDE = 'R'.```

C2

```          C2 is DOUBLE PRECISION array, dimension
(LDC, N)   if SIDE = 'L'
(LDC, N-1) if SIDE = 'R'
On entry, the (m - 1) x n matrix C2 if SIDE = 'L', or the
m x (n - 1) matrix C2 if SIDE = 'R'.

On exit, rows 2:m of P*C if SIDE = 'L', or columns 2:m of C*P
if SIDE = 'R'.```

LDC

```          LDC is INTEGER
The leading dimension of the arrays C1 and C2. LDC >= (1,M).```

WORK

```          WORK is DOUBLE PRECISION array, dimension
(N) if SIDE = 'L'
(M) if SIDE = 'R'```
Author

Univ. of Tennessee

Univ. of California Berkeley

NAG Ltd.

Definition at line 150 of file dlatzm.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page dlatzm(3) is an alias of dlatzm.f(3).

Tue Nov 28 2023 12:08:41 Version 3.12.0 LAPACK